Configuration Commands
Page 234 7750 SR OS Router Configuration Guide
message-interval
Syntax message-interval {[seconds] [milliseconds milliseconds]}
no message-interval
Context config>router>if>vrrp
Description This command configures the administrative advertisement message timer used by the master virtual
router instance to send VRRP advertisement messages and to derive the master down timer as
backup.
For an owner virtual router instance, the administrative advertisement timer directly sets the
operational advertisement timer and indirectly sets the master down timer for the virtual router
instance.
Non-owner virtual router instances usage of the message-interval setting is dependent on the state of
the virtual router (master or backup) and the state of the master-int-inherit parameter.
• When a non-owner is operating as master for the virtual router, the configured message-interval
is used as the operational advertisement timer similar to an owner virtual router instance. The
master-int-inherit command has no effect when operating as master.
• When a non-owner is in the backup state with master-int-inherit disabled, the configured mes-
sage-interval value is used to match the incoming VRRP advertisement message advertisement
interval field. If the locally configured message interval does not match the advertisement inter-
val field, the VRRP advertisement is discarded.
• When a non-owner is in the backup state with master-int-inherit enabled, the configured mes-
sage-interval is ignored. The master down timer is indirectly derived from the incoming VRRP
advertisement message advertisement interval field value.
The in-use value of the message interval is used to derive the master down timer to be used when the
virtual router is operating in backup mode based on the following formula:
(3x (in-use message interval) + (((256 - (in-use priority)) / 256) x ((256 - (in-use priority)) / 256)
The (in-use priority / 256) portion of the equation is the skew-time used to slow down virtual routers
with relatively low priority values when competing in the master election process.
The command is available in both non-owner and owner vrrp nodal contexts.
By default, a message-interval of 1 second is used.
The no form of the command reverts to the default value.
Default 1 - advertisement timer set to 1 second
Parameters seconds — The number of seconds that will transpire before the advertisement timer expires
expressed as a decimal integer.
Values 1 — 255
milliseconds milliseconds — Specifies the time interval, in milliseconds, between sending
advertisement messages.
Values 100 — 900